Editor Crashes When Undoing Paint Mode Selections

Attempting to use the paint mode tool on meshes in the level and then undo/redo the changes will cause the editor to crash.

Setup:

• Open a new Blank project.
• Open a new default level.

Repro:

1. Select the Paint mode from the Modes panel.
2. Change the paint color.
3. Click in the viewport to activate the brush.
4. Click and drag around the floor mesh.
5. Undo the full history and then redo.

Result: Editor crashes after undoing and redoing all paint mode changes.

Expected Result: Able to successfully undo and redo paint mode changes.

Frequency: 3/3

UE4Editor_MeshPaint!FEdModeMeshPaint::AddGeometryAdapter() meshpaintedmode.cpp:1023
UE4Editor_MeshPaint!FEdModeMeshPaint::CreateGeometryAdaptersForSelectedComponents() meshpaintedmode.cpp:1015
UE4Editor_UnrealEd!FEditorModeTools::PostUndo() editormodemanager.cpp:822
UE4Editor_UnrealEd!UEditorEngine::BroadcastPostUndo() editorserver.cpp:5093
UE4Editor_UnrealEd!UEditorEngine::HandleTransactorUndo() editorserver.cpp:1105
UE4Editor_UnrealEd!TBaseUObjectMethodDelegateInstance<0,UEditorEngine,TTypeWrapper<void> __cdecl() delegateinstancesimpl.h:757
UE4Editor_UnrealEd!TBaseUObjectMethodDelegateInstance<0,UEditorEngine,void __cdecl() delegateinstancesimpl.h:847
UE4Editor_UnrealEd!TBaseMulticastDelegate<void,FUndoSessionContext,bool>::Broadcast() delegatesignatureimpl.inl:922
UE4Editor_UnrealEd!UTransBuffer::Undo() editortransaction.cpp:857
UE4Editor_UnrealEd!UEditorEngine::Exec_Transaction() editorserver.cpp:5088
UE4Editor_UnrealEd!UEditorEngine::Exec() editorserver.cpp:5535
UE4Editor_UnrealEd!UUnrealEdEngine::Exec() unrealedsrv.cpp:622
UE4Editor_MainFrame!FMainFrameActionCallbacks::ExecuteExecCommand() mainframeactions.cpp:931
UE4Editor_MainFrame!TBaseStaticDelegateInstance<void __cdecl() delegateinstancesimpl.h:1018
UE4Editor_Slate!FUICommandList::ConditionalProcessCommandBindings() uicommandlist.cpp:211
UE4Editor_Slate!FUICommandList::ProcessCommandBindings() uicommandlist.cpp:155
UE4Editor_MainFrame!FMainFrameActionCallbacks::OnUnhandledKeyDownEvent() mainframeactions.cpp:176
UE4Editor_MainFrame!TTupleImpl<TIntegerSequence<unsigned int> >::ApplyAfter<FReply() tuple.h:116
UE4Editor_MainFrame!TBaseStaticDelegateInstance<FReply __cdecl() delegateinstancesimpl.h:949
UE4Editor_Slate!TBaseDelegate<FReply,FKeyEvent const & __ptr64>::Execute() delegatesignatureimpl.inl:522
UE4Editor_Slate!FSlateApplication::ProcessKeyDownEvent() slateapplication.cpp:4573
UE4Editor_Slate!FSlateApplication::OnKeyDown() slateapplication.cpp:4475
UE4Editor_Core!FWindowsApplication::ProcessDeferredMessage() windowsapplication.cpp:1474
UE4Editor_Core!FWindowsApplication::DeferMessage() windowsapplication.cpp:1985
UE4Editor_Core!FWindowsApplication::ProcessMessage() windowsapplication.cpp:750
UE4Editor_Core!FWindowsApplication::AppWndProc() windowsapplication.cpp:672
user32!<Unknown>
user32!<Unknown>
UE4Editor_Core!FWindowsPlatformMisc::PumpMessages() windowsplatformmisc.cpp:889
UE4Editor!FEngineLoop::Tick() launchengineloop.cpp:2795
UE4Editor!GuardedMain() launch.cpp:156
UE4Editor!GuardedMainWrapper() launchwindows.cpp:126
UE4Editor!WinMain() launchwindows.cpp:202
UE4Editor!__scrt_common_main_seh() exe_common.inl:264
kernel32!<Unknown>
ntdll!<Unknown>